Four common touch screen maintenance skills

Touch screen maintenance case 1:

Fault phenomenon of Siemens touch screen TP270 maintenance: power on DC24V, the screen has no light, and the current is about 230ma. Processing process: touch the screen by hand, and the buzzer echoes, indicating that the program runs normally. The 12V DC voltage of the high voltage bar is normal, and the low control voltage enable is normal. Explain that the problem is that the high-voltage circuit or lamp has been damaged. After disassembly, it was found that one end of the lamp tube was blackened, and there was still no light after replacing the lamp tube. It was found that the high-voltage transformer was also damaged. There is no such high-voltage transformer on the market, so I bought a LCD high-voltage strip with two tubes, fixed after connecting the line, and the power on is normal.

Touch screen maintenance example 2:

Fault phenomenon in repairing pws500 of hytec contact screen: there is no display on the screen after power on, and the current is about 100mA. Correction process: touch the screen by hand, the buzzer does not echo, indicating that the program is not running normally. The voltages of 3.3V, 5.1V and 12V measured by multimeter are normal. According to the user, the user tried to repair the contact screen after finding the fault. During the power on process, it showed a normal condition, but it would not work if it was powered on again after power off. It is analyzed that there is a faulty soldering at a pin of the chip, which makes the bus fault, and then the program can not run. Then, the hot-air gun is used to heat the solder foot of the dense foot chip, and the chip is pressed with tweezers to fuse the solder foot and tin from the head. After the above processing, start from the beginning, the current rises to 470ma, and everything is normal.

Touch screen maintenance example 3:

Fujitsu contact screen repair 650 suitable model: 660670253280112261026202630. Fault phenomenon: the handwriting on the touch screen is invalid, the keyboard is normal, the dial lever mouse is invalid, and the external USB mouse can be used normally. Treatment process: according to previous repair experience, it can be concluded that there is no problem with the contact lens, but the dial lever is damaged. Solve it immediately after replacing the dial lever.

Touch screen maintenance example 4:

If the contact screen does not respond, first check whether each wiring interface is loose, and then check whether there is conflict between the serial port and the stop number. If there is conflict, adjust resources to avoid conflict. Check whether there are cracks on the surface of the contact screen. If there are cracks, replace them in time. It is also necessary to check whether there is dirt on the surface of the contact screen. If so, remove it with a soft cloth. Investigate and check whether the indicator light on the control box works normally. When normal, the indicator light is green and flashes. Contact screen maintenance example 5: there is no response to contact after use. In some applications, due to the poor grounding function, the shell of the control box will be covered with a lot of static electricity, which will affect the operation electric field inside the control box, resulting in the gradual failure of contact. At this time, use a wire to ground the control box shell and start it from scratch.

The above four cases describe in detail the maintenance methods of the touch screen. If you encounter similar situations, you can also check them first and find maintenance personnel to solve the disadvantages.

Four common touch screen maintenance skills

Common faults and treatment of touch screen

In this paper, the touch screen encountered in the process of touch screen maintenance is inaccurate / can not be standard / no response / long response time. Common treatment methods summarized from experience, I hope you can help.

1. Why is the touch screen inaccurate?

a. It may be that after using the acoustic screen for a period of time, the reflection stripes around the screen are covered with dust. Please wipe it with a dry soft cloth, then power off, restart the computer and recalibrate.

b. It is possible that the reflection stripes of the acoustic screen are slightly damaged and cannot be completely repaired

2. Why can’t the touch screen be calibrated?

a. It is possible that the touch screen control card receives the operation signal before the host starts loading the touch screen driver. Please power off, restart the computer and recalibrate.

b. It is possible that after the acoustic screen has been used for a period of time, the reflection stripes around the screen are covered with a lot of dust. Although some areas can be operated, they cannot be calibrated. Please wipe them with a dry soft cloth, then power off, restart the computer and calibrate again

3. Why is the touch screen unresponsive?

a. It is possible that one of the touch screen connections to the keyboard port of the host is not connected. Please check the connection.

b. It is possible that the driver of the touch screen does not correspond to the serial port number actually installed on the touch screen. Please reinstall the driver.

c. It is possible that the host is a domestic original machine, and the installed operating system is an OEM version, which has been adjusted by the manufacturer, resulting in non-standard serial communication and incompatibility with the touch screen driver. If feasible, please format the hard disk and drive the touch screen after installing the system.

d. Check whether the host crashes. Check whether the reflection stripes on the four borders on the surface of the touch screen are scraped flat. Check whether the connection between the touch screen control cable and the host or control card is loose. For the surface acoustic wave screen, check whether the four sensors located at the three corners of the screen are damaged, cracked or contaminated by foreign matters. Check whether the control cable is damaged, especially whether the control cable around the screen and the part connected with the sensor of the surface acoustic wave touch screen are open circuit. Uninstall and reinstall the touch screen driver. Check whether the host is invaded by virus

4. Why does the touch screen have a long response time?

a. It is possible that there are moving water droplets on the touch screen. The touch screen responds to the operation of water droplets. Please wipe it with a dry soft cloth.

b. It is possible that the grade of the host is too low and the clock frequency is too low. Please replace the host.

5. Why is there no local response on the touch screen?

a. It is possible that the touch screen reflection stripe is partially covered. Please wipe it with a dry soft cloth.

b. It is possible that the touch screen reflection stripe is partially scraped off by hard objects and will not be repaired.

6. Why is the touch screen OK, but it just can’t operate the computer?

a. It is possible that the touch screen control card received the operation signal before the host started to load the touch screen driver. Please power off and start the computer again

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